Magnetic tape has long been used as a storage media for audio, video and computer information. Magnetic tape cartridges have been used extensively because they provide a convenient way to house and support a length of magnetic tape for engagement by a transducer in a tape drive while protecting the tape upon removal of the cartridge. Moreover, magnetic tape cartridges facilitate economic and compact storage of data. With the advent of widespread use of magnetic tape cartridges, the need to provide systems for storage and retrieval of such tape cartridges has resulted in a wide range of automated systems.
Typically, dozens, hundreds or even thousands of tape cartridges are stored within a media library, with each tape cartridge being stored in a particular storage slot in the media library. Responsive to a host computer request, a robotic mechanism, e.g., a robotic storage media retrieval assembly, moves along a rack to physically retrieve an appropriate tape cartridge from its associated storage slot in the media library. The robotic mechanism then moves the tape cartridge to an appropriate device, i.e. a tape drive, and inserts the tape cartridge into the device so that the requested read/write operations can be performed.
In today's world of data storage, and more specifically, storage tape libraries, data storage densities are ever-increasing. The need for greater storage capacities continues to rise, and more solutions are necessary to creatively arrange the mechanical components including tape drives, storage tapes, robotics for moving the storage tapes, cabling, tape magazines, etc., into smaller and smaller spaces within the media library. Because of the greater density of all of this componentry, increased precision is required when it comes to movement of robotics since storage tapes are stored more closely to one another. As a result, there is less free space within the media library for the robotics to sufficiently maneuver in an expeditious manner.
A specific segment of the market has recently turned to the solution of having the media libraries themselves be expandable. In such media libraries, a single robotic mechanism can move through the entire library eliminating the need to provide a separate mechanism for moving cartridges between modular libraries. As the robotic mechanisms grow in size to accommodate larger media libraries, the accuracy of these robotics necessarily must become more exacting.